1. Field of the Invention
This invention pertains to new lubricating oil additives, processes for preparing them, lubricating oil additive concentrates containing them, and lubricating oil compositions containing these additives. More particularly, this invention relates to oil-soluble, nitrogen-containing compositions prepared from sulfonate esters or sulfonyl chlorides and primary or secondary amines.
Lubricating oil compositions, particularly for use in internal combustion engines, have long performed many functions other than simply lubricating moving parts. Modern-day, highly compounded lubricating oil compositions provide anti-wear, anti-oxidant, extreme-pressure and anti-rust protection in addition to maintaining the cleanliness of the engine by detergency and dispersancy. Many lubricating oil additives are well known for accomplishing these functions. For maintaining engine cleanliness, a well-known class of ashless detergents which have been found to be particularly useful are the amine reaction products of hydrocarbyl-substituted succinic acids, i.e., the well-known succinimides.
2. Description of the Prior Art
Dietrich, U.S. Pat. No. 2,236,168, teaches the use as detergents for lubricating oils of compounds of the formula R(SO.sub.2)NR'R" wherein R is an acyclic, alicyclic or aromatic radical and R' and R" are hydrogen or alicyclic, aliphatic, heterocyclic or aromatic. The compounds are prepared by treating, for example, white oil, naphthenes, paraffin wax, etc., by conventional textbook processes, e.g., by reaction with sulfur dioxide and chlorine, to obtain random sites of sulfonation on the R group, which sites are then converted by conventional methods to the corresponding sulfonamide.
Knowles et al, U.S. Pat. No. 2,683,161, teach the stabilization, by heating to 110.degree.-300.degree. C., of aryl alkanesulfonates of the formula R.sub.1 [SC.sub.2 -OR.sub.2 ]x, prepared from a saturated aliphatic hydrocarbon which has been reacted with (1) chlorine and sulfur dioxide, and (2) a phenol. In the above formula, R.sub.1 is an aliphatic radical derived from a petroleum hydrocarbon containing saturated branched-chain hydrocarbons, preferably of 6 to 24 carbon atoms, and R.sub.2 is phenyl. The compounds of this reference are disclosed as useful as plasticizers and functional fluids.
Distler, U.S. Pat. No. 3,133,948, discloses a process for preparing vinylsulfonates of aromatic hydroxy compounds. This process involves reacting carbyl sulfate with an aromatic hydroxy compound in an aqueous alkaline medium at a pH between 7.5 and 11.5 to yield a phenyl vinylsulfcnate. Suitable aromatic hydroxy compounds include ortho- and para-chlorophenol. Carbyl sulfate is prepared from the reaction of ethylene with sulfur trioxide or oleum.
Klass et al., U.S. Pat. No. 3,158,639, state that carbyl sulfate has been known since 1836 and teach that it may be prepared by reacting ethylene with sulfur trioxide at a 1:2 mol ratio either in solution or in the vapor phase, usually at room temperature or lower to avoid charring.
Friedrichsen ard Distler, U.S. Pat. No. 3,205,249, disclose aryl esters of unsaturated sulfonic acids. The esters are prepared by reacting an olefin containing at least 1 methyl and/or methylene group adjacent to the double bond linkage with a vinylsulfonic acid aryl ester at temperature between 100.degree.-300.degree. C. Suitable olefins contain between 3 and 20 carbon atoms. The compounds of this reference are disclosed as useful as plasticizers and textile auxiliaries.
Ballard et al., U.S. Pat. No. 3,238,257, disclose N-tertiary-alkyl alkanesulfonamides of a formula R--SO.sub.2 --NH--R.sup.1 useful in petroleum distillate fuels as anti-icing, anti-corrosion and carburetor detergency additives. In this formula, R is a saturated alkyl radical containing 12 to 30 carbon atoms and R.sup.1 is a tertiary alkyl group having 8 to 22 carbon atoms. Preferred compounds contain a total of 25 to 35 carbon atoms between R and R.sup.1. These sulfonamides are prepared by reacting an aliphatic hydrocarbon with gaseous sulfur dioxide and chlorine in the presence of actinic light to obtain a hydrocarbonsulfonyl chloride, which is then reacted with the desired amine. In a preferred embodiment, the aliphatic hydrocarbon is obtained from sulfochlorination of number 40 white oil, which is a highly acid-washed paraffin petroleum fraction having an average of 16 to 20 carbon atoms.
Stuart, U.S. Pat. No. 3,325,418, teaches a polysulfonamide-substituted polyclefin having a molecular weight of 200,000-1,000,000 which is prepared by treating the polyolefin with sulfur dioxide and chlorine gas to yield a product which is used for improving the viscosity index and as a detergent in lubricating oils.
Brasch, U.S. Pat No. 3,352,782, teaches amido sulfates of the formula ##STR1## wherein R.sup.1 is an organic group, R.sup.2 is H or an organic group, and R.sup.3 and R.sup.4 are inter alia H or polyamine. These compounds, prepared by reacting an olefin polymer with chlorosulfonic acid and then with an amine, are useful as detergents in lubricating oil compositions.